Depends on where you live. If you need it for smog inspections, you'll need to replace. If you take the system off, it won't really hurt anything performance-wise. The engine has done what it's going to do with the fuel. The AIR just injects fresh air to the exhaust at the exhaust manifolds to burn up any residual fuel. That's for cleaner emissions. Again, if you need it for emission testing, you may have to replace it. Take the belt off and roll with it if you don't care. Or you could clean up the entire area by deleting the system. It's up to you and any local emission law/inspection requirements.
What year
H/O?
1983
H/O:
7842852 if you have cruise. Stamped FY.
7838575 if you do not have cruise. Stamped FP. I do not know the specific difference between these two.
1984
H/O:
7838575
NAPA p/n equivalent: NAP 51245 for the 7842852, and NAP 51220 for the 7838575.
Cardone: 32-245, 149.99 plus 1.00 core, and 32-220, $121.99 plus 2.00 core at O'reilly. Hmmm the last 3 numbers seem to correlate with the NAPA numbers.
Advance sells Cardone as well. Approx same price as O'reilly. I noticed lifetime replacement at Advance.....
Interesting RockAuto and NAPA show these items out of stock online...probably getting harder and harder to find good cores. I dunno. Even GM started selling refurbished ones after a while until they discontinued them. For the same price as new ones!
Never had one apart so I have no idea what's inside of them. Probably some lobes and reed valves.